The present invention relates to an environmental test method and system.
A conventional environmental test system is used to apply a voltage on a member to be tested while adjusting the internal temperature in the test chamber in which the member is installed. An example of these types of conventional environmental test systems is disclosed in Japanese Unexamined Patent Publication 2002-286811.
FIG. 8 is a partially cross sectional view of a part of the environmental test system according to the publication. This publication shows the environmental test systems that individually carry out a plurality of optical communication modules to be tested.
In FIG. 8, the environmental test system is provided with an individual test module 99, a test chamber 100 contained in the individual test module 99, and a test board 160 mounted on a bottom wall of the test chamber 100. A member 150 to be tested is set on the test board 160.
The environmental test system has a power supply cable 170 and an optical fiber 180 which are connected between the member 150 and a test unit (not shown) located on the outside of the test module 99, respectively.
The environmental test system is provided with a heating device 110 and a cooling device 120 which are contained in the test module 99. The heating device 110 and the cooling device 120 are capable of controlling the temperature of air existing in the test module 99, and a fan 130 for moving the temperature-controlled air toward one end portion of one wall of the test chamber 100.
At least one slit is formed at the one end portion of the one wall of the test chamber 100. A plurality of wind direction control plates 190 are attached to the inner surface of the one end portion of the chamber's one wall. The wind-direction control plates 190 are directed, for example, toward the member 150.
The test module 99 is provided with a door 140 openable and closable at the other wall of the test chamber 100. The environmental test system is further equipped with a temperature sensing unit 200 for sensing the internal temperature in the test chamber 100.
Opening and closing of the door 140 allows the member 150 to be carried in and out of the test chamber 100. That is, the test board 160 on which the member 150 is mounted is inserted through the opening and closing of the door 140 into the test chamber 100. After the installation of the member 150, the test module 99 and the test chamber 100 are hermetically closed.
The heating device 110 and the cooling device 120 heat and cool the air existing in the test module 99 to control the temperature of it, and the temperature-controlled air enters the test chamber 100 through the slit to be directed by the wind-direction control plates 190. The controlled air determines the internal temperature in the test chamber 100 to predetermined temperatures, such as a first temperature requirement of 25 degrees, a second requirement of minus 40 degrees, and a third temperature requirement of 85 degrees.
A power supply unit in the test unit starts to supply power through the power supply cable 170 to the member 150. When the internal temperature reaches one of the predetermined temperatures, the environmental test, such as an optical signal communication test, is carried out according to the predetermined test items for the environmental test.
In this disclosed environmental test system, however, the opening and closing of the door 140 in inserting the member 150 into the inside of test chamber 100 causes air outside of the test module 99 to enter the inside of test chamber 100. This entered air causes dew on the surface of the member 150 in the process of controlling the internal temperature of the test chamber 100 from low temperature to high temperature.